The newly available PLib Standard (officially the ISO 13584 Standard series "Parts Library") has defined a model and an exchange format for digital libraries of technical components. The major benefits of this approach include : productivity increase (the components are not modeled several times), quality increase (the data models are guaranteed by the supplier of the library) and product data storage / exchange efficiency (in product data a component is only represented by a reference). Developed in the same ISO committee as STEP, PLib is fully inter-operable with STEP. In PLib libraries, component representations may be defined as STEP data. In STEP product data, PLib components may be represented by simple references. This presentation gives an overview of the PLib information model and outlines the document structure of ISO 13584. It discusses the use of PLib for the design and the use of on-line electronic catalogues. Then, some of the tools developed in several ESPRIT projects to generate, on the supplier site (catalogue generators), and to use, on the customer site (Library Management System-LMS), PLib conforming libraries are presented.